Steel P690QL1
EN 1.8881
A quenched and tempered fine-grain nickel-alloyed structural steel with minimum yield strength of 690 MPa, offering good low-temperature toughness for heavy-wall pressure vessels and structural components.
Reference datasheet — P690QL1 is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the QT condition
P690QL1 tempers and conditions
P690QL1 is supplied in 4 conditions, soft to hard. QT is the default FabDigit quotes; the values on this page are for it.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
QT | Maximum thickness range; lowest guaranteed strength due to reduced quench severity in the core. | 670 | 790 | 17 | 23 HRC | 6.9 % IACS |
QT | Heavy-wall plate; thickness-derated proof strength for vessel shells and forged-like sections. | 690 | 800 | 17 | 24 HRC | 6.9 % IACS |
Quenched, tempered and stress relieved / PWHT simulated | Choose when the fabricated vessel receives PWHT; properties must be verified on simulated-heat-treated coupons because strength drops. | 700 | 800 | 18 | 24 HRC | 6.9 % IACS |
QTDefault Quenched and tempered | Standard delivery condition of P690QL1 plate; full 690 MPa minimum yield with -40 °C impact guarantee. | 730 | 830 | 17 | 26 HRC | 6.9 % IACS |
What is P690QL1?
A quenched and tempered fine-grain nickel-alloyed structural steel with minimum yield strength of 690 MPa, offering good low-temperature toughness for heavy-wall pressure vessels and structural components. P690QL1 has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,440°C (2,624 °F). P690QL1 has a yield strength of 730 MPa (106 ksi) and a tensile strength of 830 MPa (120 ksi) — stronger than 83% of steel grades. Elongation at break is 17% and the elastic modulus is 210 GPa (30.5 Msi).
What is P690QL1 used for?
- pressure vessels
- mobile crane booms
- heavy structural frames
- earthmoving equipment
- offshore structures
Advantages
- Tough — resists crack growth — 130 MPa·√m (118.3 ksi·√in), better than 89% of steel grades
- High strength — 730 MPa (106 ksi), better than 83% of steel grades
Limitations
- Difficult to machine — 40/100, worse than 77% of steel grades
P690QL1 properties
Typical room-temperature values for P690QL1-QT; bars are the position among steel grades.
Physical3
P690QL1 has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,440°C (2,624 °F).
Mechanical16
P690QL1 has a yield strength of 730 MPa (106 ksi) and a tensile strength of 830 MPa (120 ksi) — stronger than 83% of steel grades. Elongation at break is 17% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
P690QL1 is rated for continuous service to 400°C (752 °F). It conducts heat at 36 W/m·K (20.8 BTU/hr·ft·°F), worse than 73% of steel grades. Thermal expansion is 12 µm/m·K (6.67 µin/in·°F).
Electrical3
P690QL1 conducts electricity at 6.9 % IACS, worse than 76% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (13/100), better than 66% of steel grades.
Sustainability4
Producing a kilogram of P690QL1 takes about 30 MJ of energy and emits 2.3 kg of CO₂ — more than 56% of steel grades. Typical recycled content is 25%.
Manufacturability7
P690QL1's machinability is fair (40/100, worse than 77% of steel grades); weldability good (65/100); formability fair (45/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the steel family
Yield strength against density for every steel grade FabDigit runs. P690QL1 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with P690QL1
Is P690QL1 easy to machine?
Machine as ~260 HB alloy steel: rigid setup, coated carbide, moderate speeds and positive rake; avoid rubbing that work-hardens the surface.
Can P690QL1 be welded?
Weldable with low-hydrogen consumables; preheat typically 100–150 °C (thickness/CEV dependent), control interpass ≤ 200 °C and heat input to protect HAZ toughness, PWHT below the tempering temperature only.
Can P690QL1 be formed, bent or molded?
Cold bend with generous inside radii (≈3–5 t transverse) and dies aligned to rolling direction; hot forming above the tempering temperature destroys the Q&T properties and requires re-heat-treatment.
P690QL1 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| Cladle analysis | ≤ 0.2 | 0.16 |
| Si | ≤ 0.8 | 0.3 |
| Mn | 0.8 – 1.7 | 1.3 |
| P | ≤ 0.02 | 0.01 |
| S | ≤ 0.01 | 0 |
| Altotal Al, grain refining | ≥ 0.02 | 0.04 |
| Cr | ≤ 1.5 | 0.5 |
| Cu | ≤ 0.5 | 0.2 |
| Mo | ≤ 0.7 | 0.45 |
| Ni | ≤ 2.5 | 1.5 |
| Nb | ≤ 0.06 | 0.03 |
| Ti | ≤ 0.05 | 0.02 |
| V | ≤ 0.12 | 0.05 |
| Zr | ≤ 0.05 | |
| B | ≤ 0.01 | 0 |
| N | ≤ 0.02 | 0.01 |
| Fe | balance |
What surface finishes work on P690QL1?
Not anodizable — shot-blast to Sa 2½ then zinc-rich epoxy primer or metallize; hot-dip galvanizing needs caution at this strength level (LME/hydrogen risk).
Surface treatments FabDigit runs on steel parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Organic Coating
Black / Phosphate
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Steel P690QL1 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- EN / DIN / Werkstoff-Nr.
- 1.8881
How much does P690QL1 cost?
P690QL1 is a budget-cost steel ($), cheaper than about 90% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
P690QL1 — frequently asked
What is P690QL1 used for?
P690QL1 is typically used for pressure vessels, mobile crane booms, heavy structural frames, earthmoving equipment and offshore structures. In short: 690 MPa weldable plate; low-temperature impact qualified; weight-saving structural grade.
What is the yield strength of P690QL1?
P690QL1 has a typical yield strength of 730 MPa (106 ksi) and a tensile strength of 830 MPa (120 ksi) — stronger than 83% of steel grades. Strength varies by condition: see the 4 listed tempers.
Is P690QL1 easy to machine?
Not especially — machinability is rated fair (40/100, worse than 77% of steel grades). Machine as ~260 HB alloy steel: rigid setup, coated carbide, moderate speeds and positive rake; avoid rubbing that work-hardens the surface.
Can P690QL1 be welded?
Yes — weldability is rated good (65/100). Weldable with low-hydrogen consumables; preheat typically 100–150 °C (thickness/CEV dependent), control interpass ≤ 200 °C and heat input to protect HAZ toughness, PWHT below the tempering temperature only.
What surface finishes work on P690QL1?
Not anodizable — shot-blast to Sa 2½ then zinc-rich epoxy primer or metallize; hot-dip galvanizing needs caution at this strength level (LME/hydrogen risk).
Can P690QL1 be formed, bent or molded?
Cold bend with generous inside radii (≈3–5 t transverse) and dies aligned to rolling direction; hot forming above the tempering temperature destroys the Q&T properties and requires re-heat-treatment.
What is the maximum service temperature of P690QL1?
P690QL1 is rated for continuous use to about 400°C (752 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does P690QL1 cost?
P690QL1 is a budget-cost steel ($), cheaper than about 90% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- EN 10028-6 Flat products made of steels for pressure purposes — Weldable fine grain steels, quenched and tempered — CEN (2017)
- EN 10025-6 Hot rolled products of structural steels — Flat products of high yield strength structural steels in the quenched and tempered condition — CEN (2019)
- ASM Handbook Vol. 1: Properties and Selection — Irons, Steels and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol. 19: Fatigue and Fracture — ASM International (1996)
- Quenched and tempered 690 MPa pressure vessel plate datasheets (Dillinger / SSAB / Voestalpine class products) — various mills (2023)
- Mysteel / SMM (2025)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.